Also known as Asparagine synthetase B [glutamine-hydrolyzing] (AS-B).AsnA and AsnB are redundant; an asparagine auxotrophy requires that both genes be mutated. [More information is available at EcoGene: EG10092]. Asparagine synthetase B (AsnB) is one of two asparagine synthetases in Escherichia coli, catalyzing the glutamine-dependent and ammonia-dependent conversion of aspartate to asparagine. [More information is available at EcoCyc: EG10092].